1. Field of the Invention
This invention relates to an ink ribbon. More particularly, it is concerned with an ink ribbon for use in a heat transfer printing device, a typewriter, and so forth, wherein the ribbon is made by applying a solid ink material on a web-formed base member, and is capable of transferring the ink on the base member to a printing sheet in desired patterns by applying pressure or heat to the ribbon.
2. Description of Prior Art
It has so far been a practice that this kind of ink ribbon has a pressure-fixing type solid oak coated on one surface side of the base member (or substrate) made of a synthetic resin film such as polyester, etc., in case it is used in an impact type printing device such as a typewriter, etc., and a heat-melting type solid ink coated on the substrate, in case it is used in a heat transfer printing device.
The ink ribbon is opposed to a printing sheet with its ink-coated surface facing the sheet and transfer of the ink on the ribbon is done by applying pressure or heat to the other surface of the ribbon i.e., the substrate side, in desired patterns.
The ribbon after use bears information as printed left on it in the form of negative images, because of the solid ink on the substrate having been transferred to the printing sheet as the print patterns. In this case, if the ink and the substrate to bear the ink on it are of different color, e.g., black for the ink and colorless transparency for the substrate, the contents of the printed information can be retrieved at a glance, which would possibly invite leakage of important and secret information outside, if the ink ribbon is improperly disposed of after its use.